Isometric Exercise Training and Arterial Hypertension: An Updated Review.

Hypertension is recognised as a leading attributable risk factor for cardiovascular disease and premature mortality. Global initiatives towards the prevention and treatment of arterial hypertension are centred around non-pharmacological lifestyle modification. Exercise recommendations differ between professional and scientific organisations, but are generally unanimous on the primary role of traditional aerobic and dynamic resistance exercise. In recent years, isometric exercise training (IET) has emerged as an effective novel exercise intervention with consistent evidence of reductions in blood pressure (BP) superior to that reported from traditional guideline-recommended exercise modes. Despite a wealth of emerging new data and endorsement by select governing bodies, IET remains underutilised and is not widely prescribed in clinical practice. This expert-informed review critically examines the role of IET as a potential adjuvant tool in the future clinical management of BP. We explore the efficacy, prescription protocols, evidence quality and certainty, acute cardiovascular stimulus, and physiological mechanisms underpinning its anti-hypertensive effects. We end the review with take-home suggestions regarding the direction of future IET research.

Central and peripheral mechanisms underlying postexercise hypotension: a scoping review.

Blood pressure (BP) reduction occurs after a single bout of exercise, referred to as postexercise hypotension (PEH). The clinical importance of PEH has been advocated owing to its potential contribution to chronic BP lowering, and as a predictor of responders to exercise training as an antihypertensive therapy. However, the mechanisms underlying PEH have not been well defined. This study undertook a scoping review of research on PEH mechanisms, as disclosed in literature reviews. We searched the PubMed, Web of Science, Scopus, Cumulated Index to Nursing and Allied Health Literature (CINAHL), Cochrane Library, and Sport Discus databases until January 2023 to locate 21 reviews - 13 narrative, four systematic with 102 primary trials, and four meta-analyses with 75 primary trials involving 1566 participants. We classified PEH mechanisms according to major physiological systems, as central (autonomic nervous system, baroreflex, cardiac) or peripheral (vascular, hemodynamic, humoral, and renal). In general, PEH has been related to changes in autonomic control leading to reduced cardiac output and/or sustained vasodilation. However, the role of autonomic control in eliciting PEH has been challenged in favor of local vasodilator factors. The contribution of secondary physiological outcomes to changes in cardiac output and/or vascular resistance during PEH remains unclear, especially by exercise modality and population (normal vs. elevated BP, young vs. older adults). Further research adopting integrated approaches to investigate the potential mechanisms of PEH is warranted, particularly when the magnitude and duration of BP reductions are clinically relevant. (PROSPERO CRD42021256569).

The Role of Exercise in Statin-Associated Muscle Symptoms Outcomes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Objective: To provide a synthesis of randomized controlled trials (RCTs) investigating statin-associated muscle symptoms (SAMS) in adults who underwent exercise training intervention. Patients and Methods: We systematically searched 5 electronic databases for placebo-controlled RCTs through January 31, 2023. We included short-term and long-term exercise interventions that compared the efficacy and safety of exercise+statin vs exercise+placebo in healthy adults and reported SAMS preintervention and postintervention. Publication bias and methodological study quality assessments were performed. Results: Five of 454 potentially qualifying RCTs met the inclusion criteria, all short-term exercise RCTs. Participants were predominantly physically inactive young to middle-aged (M=37.2 y) men (57%), 252 (49%) who were on statin therapy, and 271 (53%) on placebo. Of the 3 RCTs providing qualitative SAMS results, 19 (9%) out of 220 participants reported SAMS on exercise+statin and 10 (4%) out of 234 reported SAMS on exercise+placebo. There was no difference between exercise+statin vs exercise+placebo for maximal oxygen consumption (d=-0.18; 95% CI, -0.37 to 0.00; P=.06) or creatine kinase after short-term exercise (d=0.59; 95% CI, -0.06 to 1.25; P=.08). Participants in the exercise+statin group reduced low-density lipoprotein cholesterol vs exercise+placebo (d=-1.84; 95% CI, -2.28 to -1.39; P<.001). Most of the RCTs exhibited low levels of risk of bias (k=4, 80%) and achieved moderate methodological study quality (75.0%±5.2%). Conclusion: Self-reported SAMs tended to be 5% greater after short-term exercise in statin users compared with placebo, although this difference did not achieve statistical significance. There remains an important need for placebo-controlled RCTs investigating the prevalence of statin-induced SAMS during exercise training.

Reliability and Time Course of Postexercise Hypotension during Exercise Training among Adults with Hypertension.

Postexercise hypotension (PEH), or the immediate decrease in blood pressure (BP) lasting for 24 h following an exercise bout, is well-established; however, the influence of exercise training on PEH dynamics is unknown. This study investigated the reliability and time course of change of PEH during exercise training among adults with hypertension. PEH responders (n = 10) underwent 12 weeks of aerobic exercise training, 40 min/session at moderate-to-vigorous intensity for 3 d/weeks. Self-measured BP was used to calculate PEH before and for 10 min after each session. The intraclass correlation coefficient (ICC) and Akaike Information Criterion (AIC) determined PEH reliability and goodness-of-fit for each week, respectively. Participants were obese (30.6 ± 4.3 kg∙m-2), middle-aged (57.2 ± 10.5 years), and mostly men (60%) with stage I hypertension (136.5 ± 12.1/83.4 ± 6.7 mmHg). Exercise training adherence was 90.6 ± 11.8% with 32.6 ± 4.2 sessions completed. PEH occurred in 89.7 ± 8.3% of these sessions with BP reductions of 9.3 ± 13.1/3.2 ± 6.8 mmHg. PEH reliability was moderate (ICC ~0.6). AIC analysis revealed a stabilization of maximal systolic and diastolic BP reductions at 3 weeks and 10 weeks, respectively. PEH persisted throughout exercise training at clinically meaningful levels, suggesting that the antihypertensive effects of exercise training may be largely due to PEH. Further studies in larger samples and under ambulatory conditions are needed to confirm these novel findings.

Comprehensiveness, Accuracy, and Readability of Exercise Recommendations Provided by an AI-Based Chatbot: Mixed Methods Study.

BACKGROUND: Regular physical activity is critical for health and disease prevention. Yet, health care providers and patients face barriers to implement evidence-based lifestyle recommendations. The potential to augment care with the increased availability of artificial intelligence (AI) technologies is limitless; however, the suitability of AI-generated exercise recommendations has yet to be explored. OBJECTIVE: The purpose of this study was to assess the comprehensiveness, accuracy, and readability of individualized exercise recommendations generated by a novel AI chatbot. METHODS: A coding scheme was developed to score AI-generated exercise recommendations across ten categories informed by gold-standard exercise recommendations, including (1) health condition-specific benefits of exercise, (2) exercise preparticipation health screening, (3) frequency, (4) intensity, (5) time, (6) type, (7) volume, (8) progression, (9) special considerations, and (10) references to the primary literature. The AI chatbot was prompted to provide individualized exercise recommendations for 26 clinical populations using an open-source application programming interface. Two independent reviewers coded AI-generated content for each category and calculated comprehensiveness (%) and factual accuracy (%) on a scale of 0%-100%. Readability was assessed using the Flesch-Kincaid formula. Qualitative analysis identified and categorized themes from AI-generated output. RESULTS: AI-generated exercise recommendations were 41.2% (107/260) comprehensive and 90.7% (146/161) accurate, with the majority (8/15, 53%) of inaccuracy related to the need for exercise preparticipation medical clearance. Average readability level of AI-generated exercise recommendations was at the college level (mean 13.7, SD 1.7), with an average Flesch reading ease score of 31.1 (SD 7.7). Several recurring themes and observations of AI-generated output included concern for liability and safety, preference for aerobic exercise, and potential bias and direct discrimination against certain age-based populations and individuals with disabilities. CONCLUSIONS: There were notable gaps in the comprehensiveness, accuracy, and readability of AI-generated exercise recommendations. Exercise and health care professionals should be aware of these limitations when using and endorsing AI-based technologies as a tool to support lifestyle change involving exercise.

Evaluation of Exercise Mobile Applications for Adults with Cardiovascular Disease Risk Factors.

OBJECTIVE: To conduct a systematic review to determine if there are exercise mobile applications (apps) that can produce evidence-based, individualized exercise plans. MATERIALS AND METHODS: We searched the Apple Store and Google Play for exercise apps with terms related to exercise and health. Exercise apps were eligible if they: (1) had a ≥4 out of 5 overall rating with ≥1000 reviews; (2) were free to download; and (3) were not gender specific. Exercise apps were evaluated via the evidence-based exercise prescription (ExRx) standards of the American College of Sports Medicine (ACSM) and American Heart Association. For the exercise app evaluation criteria, an app was included if it (1) was evidence-based; (2) contained a preparticipation health screening protocol; (3) built a cardiovascular disease (CVD) risk factor profile; (4) prioritized one chronic disease or health condition to focus on; (5) framed the exercise plan by the frequency, intensity, time, and type principle (FITT) of ExRx; and (6) specified special considerations. RESULTS: Of the 531 potentially qualifying apps, 219 qualified. The qualifying apps were rarely evidenced-based (0.5%) or had a preparticipation screening protocol (3.7%). Only 27.7% built CVD risk factor profiles. Most apps (64.8%) focused on body image and/or athletic performance. Only 4.3% focused on chronic diseases or health conditions, while the remainder (34.5%) did not disclose a focus. No app framed the exercise plans by the FITT of ExRx. Only 1.4% of the apps specified special considerations. CONCLUSION: There are no commercially available exercise apps that generate an evidence-based, individualized exercise plan for adults with CVD risk factors.

Increasing Lifestyle Walking by 3000 Steps per Day Reduces Blood Pressure in Sedentary Older Adults with Hypertension: Results from an e-Health Pilot Study.

Increasing daily steps by an additional 3000 steps/day on 5 days/week equates to ~150 min/week of aerobic physical activity to meet the physical activity guidelines; however, its effectiveness for blood pressure control in older adults with hypertension is unknown. A 20-week, single-arm, pilot e-health lifestyle walking intervention was conducted in 21 sedentary older adults (73 ± 5 years old) with hypertension (13 female, 8 male) to investigate the effectiveness of increasing daily steps by an additional 3000 steps/day for blood pressure control. The intervention consisted of two phases, with behavior change assistance provided during the first active phase (weeks 1-10) to help reach step goals and minimal assistance provided during the second self-maintenance phase (weeks 11-20). Nineteen participants (91%) completed both the 10- and 20-week assessments. The participants wore the pedometer for ≥10 h on 97% of the days over 20 weeks. They significantly increased average steps/day from 3899 ± 2198 at baseline to 6512 ± 2633 at 10 weeks and 5567 ± 2587 at 20 weeks. After 20 weeks, both systolic (137 ± 10 to 130 ± 11 mm Hg, p < 0.001) and diastolic (81 ± 6 to 77 ± 6 mm Hg, p = 0.01) blood pressure improved. The response was consistent in participants with (n = 8) and without (n = 13) anti-hypertensive medication. The results of our lifestyle walking intervention are encouraging for reducing blood pressure in older adults with hypertension; however, larger randomized, controlled trials need to be performed to confirm these findings.

Effects of foam rolling and strength training on post exercise hypotension in normotensive women: A cross-over study.

Foam rolling (FR) has recently become very popular among athletes and recreational exercisers and is often used during warm up prior to strength training (ST) to induce self-myofascial release. The purpose was to examine the acute effects of ST and FR performed in isolation or in combination on blood pressure (BP) responses during recovery in normotensive women. Sixteen normotensive and strength trained women completed four interventions: 1) rest control (CON), 2) ST only, 3) FR only, and 4) ST immediately followed by FR (ST + FR). ST consisted of three sets of bench press, back squat, front pull-down, and leg press exercises at 80% of 10RM. FR was applied unilaterally in two sets of 120 s to each of the quadriceps, hamstring, and calf regions. Systolic (SBP) and diastolic (DBP) BP were measured before (rest) and every 10 min, for 60 min, following (Post 10-60) each intervention. Cohen's d effect sizes were calculated to indicate the magnitude effect by the formula d = Md/Sd, where Md is the mean difference and Sd is the standard deviation of differences. Cohen's d effect-sizes were defined as small (≥0.2), medium (≥0.5), and large (≥0.8). There were significant reductions in SBP for ST at Post-50 (p < 0.001; d = -2.14) and Post-60 (p < 0.001; d = -4.43), for FR at Post-60 (p = 0.020; d = -2.14), and for ST + FR at Post-50 (p = 0.001; d = -2.03) and Post-60 (p < 0.001; d = -2.38). No change in DBP was observed. The current findings suggest that ST and FR performed in isolation can acutely reduce SBP but without an additive effect. Thus, ST and FR can both be used to acutely reduce SBP and, importantly, FR can be added to a ST regimen without furthering the SBP reduction during recovery.

Exercise and Protein Supplementation Recommendations for Older Adults With Sarcopenic Obesity: A Meta-Review.

This systematic meta-review evaluated the effects of exercise with and without protein interventions on muscle strength and function in older adults with sarcopenic obesity. PubMed, Cochrane Database of Systematic Reviews, Cumulative Index to Nursing and Allied Health Literature, Scopus, and SPORTDiscus databases were searched through February 2021 for relevant systematic reviews and meta-analyses with aerobic, resistance, and/or combined training interventions with and without protein supplementation in older adults ≥ 65 years with sarcopenic obesity. This meta-review showed that exercise with and without protein supplementation improved body composition (i.e., decreased percentage body fat) and functional outcomes (i.e., gait speed and grip strength). Because the current literature is limited, determining the effects of exercise and combined protein supplementation in this population requires further investigation. In the meantime, protein recommendations should align with general sarcopenia recommendations. Based upon available findings, tentative exercise recommendations to optimize health outcomes in this population are proposed.

The Relationship between Postexercise Hypotension and Heart Rate Variability before and after Exercise Training.

Because data are scarce, we examined the relationship between postexercise hypotension (PEH) and heart rate variability (HRV) before and after aerobic exercise training among adults with hypertension. Participants completed a 12 w aerobic training program. Before and after training, they performed a peak graded exercise stress test (GEST) and nonexercise control (CONTROL) and were left attached to an ambulatory BP monitor. Prior to CONTROL, HRV was measured supine for 5 min using a 12-lead electrocardiogram (ECG). The participants (n = 18) were middle-aged (52.1 ± 11.7 y) and 50% men with hypertension (131.7 ± 9.8/85.9 ± 8.5 mmHg) and obesity (30.0 ± 3.7 kg·m-2). Before training, ambulatory systolic BP (ASBP) and diastolic ABP (ADBP) decreased by 3.2 ± 2.1 mmHg and 2.5 ± 1.5 mmHg, respectively, from baseline after the GEST versus CONTROL (p < 0.05). After training, ASBP tended to decrease by 3.5 ± 2.2 mmHg (p = 0.055) and ADBP decreased by 1.7 ± 2.5 mmHg (p = 0.001) from baseline after the GEST versus CONTROL. Before training, HRV high frequency (HFms2) (ß = -0.441), age (ß = 0.568), and resting SBP (ß = 0.504) accounted for 66.8% of the ASBP response (p = 0.001), whereas the low frequency (LF)/HF ratio (ß = 0.516) and resting DBP (ß = 0.277) accounted for 35.7% of the ADBP response (p = 0.037). After training, the standard deviation of NN intervals (SDNN) (ß = -0.556), age (ß = 0.506), and resting SBP (ß = 0.259) accounted for 60.7% of the ASBP response (p = 0.004), whereas SDNN (ß = -0.236) and resting DBP (ß = 0.785) accounted for 58.5% of the ADBP response (p = 0.001). Our preliminary findings show that adults with hypertension and parasympathetic suppression (i.e., lower SDNN and HFms2 and higher LF/HF) may elicit PEH to the greatest degree independent of training status versus adults with parasympathetic predominance, suggesting that resting HRV may be an important determinant of PEH.

Aerobic exercise improves central blood pressure and blood pressure variability among patients with resistant hypertension: results of the EnRicH trial.

Central blood pressure (BP) and BP variability are associated with cardiovascular disease risk. However, the influence of exercise on these hemodynamic parameters is unknown among patients with resistant hypertension. The EnRicH (The Exercise Training in the Treatment of Resistant Hypertension) was a prospective, single-blinded randomized clinical trial (NCT03090529). Sixty patients were randomized to a 12-week aerobic exercise program or usual care. The outcome measures include central BP, BP variability, heart rate variability, carotid-femoral pulse wave velocity, and circulating cardiovascular disease risk biomarkers including high-sensitivity C-reactive protein, angiotensin II, superoxide dismutase, interferon gamma, nitric oxide, and endothelial progenitor cells. Central systolic BP decreased by 12.22 mm Hg (95% CI, -1.88 to -22.57, P = 0.022) as did BP variability by 2.85 mm Hg (95% CI, -4.91 to -0.78, P = 0.008), in the exercise (n = 26) compared to the control group (n = 27). Interferon gamma -4.3 pg/mL (95%CI, -7.1 to -1.5, P = 0.003), angiotensin II -157.0 pg/mL (95%CI, -288.1 to -25.9, P = 0.020), and superoxide dismutase 0.4 pg/mL (95%CI, 0.1-0.6, P = 0.009) improved in the exercise compared to the control group. Carotid-femoral pulse wave velocity, heart rate variability, high-sensitivity C-reactive protein, nitric oxide, and endothelial progenitor cells were not different between groups (P > 0.05). In conclusion, a 12-week exercise training program improved central BP and BP variability, and cardiovascular disease risk biomarkers in patients with resistant hypertension. These markers are clinically relevant as they are associated with target organ damage and increased cardiovascular disease risk and mortality.

Exercise for counteracting weight recurrence after bariatric surgery: a systematic review and meta-analysis of randomized controlled trials.

Exercise is recommended to prevent post-surgical weight recurrence. Yet, whether exercise interventions are efficacious in this regard has not been systematically evaluated. Moreover, clinicians lack evidence-based information to advise patients on appropriate exercise frequency, intensity, time, and type (FITT) for preventing weight recurrence. Thus, we conducted a meta-analysis of randomized controlled trials (RCTs) involving exercise interventions specifying FITT and weight measurement ≥12 months post-surgery. We reviewed scientific databases up through February 2022 for RCTs comparing exercise interventions reporting FITT and a nonexercise control group on weight ≥12 months post-surgery. Procedures following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses were registered at the international prospective register of systematic reviews (PROSPERO: CRD42022342337). Of 1368 studies reviewed, 5 met inclusion criteria (n = 189; 47.8 ± 4.2 yr, 36.1 6 ± 3.8 kg·m2, 83.2 ± 9.5% female; 61.7% underwent Roux-en-Y gastric bypass). Exercise interventions were largely supervised, lasted 12-26 weeks, and prescribed 80-210 minutes/week of moderate-to-vigorous intensity combined aerobic and resistance exercise over ≤5 days. Within-group effects showed non-statistically significant weight loss for exercise (d = - .15, 95% confidence interval [CI]: -1.96, 1.65; -1.4 kg; P = .87) and weight gain for control (d = .11, 95% CI: -1.70,1.92; +1.0 kg; P = .90), with no difference between these groups (d = -2.26, 95% CI: -2.07, 1.55; -2.4 kg; P = .78). Exercise elicited an additional 2.4 kg weight loss versus control, although this effect was small and statistically non-significant. Ability to draw definitive conclusions regarding efficacy of exercise interventions for counteracting post-surgical weight recurrence was limited by the small number of trials and methodological issues. Findings highlight the need for more rigorous RCTs of exercise interventions specifically designed to reduce post-surgical weight recurrence.

The effects of an acute weight stigma exposure on cardiovascular reactivity among women with obesity and hypertension: A randomized trial.

OBJECTIVE: Weight stigma induces cardiovascular health consequences for people with obesity. How stigma affects cardiovascular reactivity in individuals with both obesity and hypertension is not known. METHODS: In a randomized experiment, we assessed the influence of two video exposures, depicting either weight stigmatizing (STIGMA) or non-stigmatizing (NEUTRAL) scenes, on cardiovascular reactivity [resting blood pressure (BP), heart rate (HR), ambulatory BP (ABP), and ambulatory HR (AHR)], among women with obesity and high BP (HBP; n=24) or normal BP (NBP; n=25). Systolic ABP reactivity was the primary outcome. Laboratory BP and HR were measured before/during/following the videos, and ABP and AHR were measured over 19 hours (10 awake hours, 9 sleep hours) upon leaving the laboratory. A repeated measures ANCOVA tested differences in BP and HR changes from baseline in the laboratory and over ambulatory conditions between the two groups after each video, controlling for body mass index, baseline BP and HR. RESULTS: Laboratory SBP/DBP increased 5.5+7.3/2.4+8.8mmHg more in women with HBP than NBP following the STIGMA versus NEUTRAL video (Ps<0.05). For the primary outcome, ABP increased more in HBP than NBP over sleep (SBP/DBP=4.2+20.6/4.7+14.2mmHg; Ps<0.05) following the STIGMA versus NEUTRAL video, as did HR during sleep (7.5+15.7bpm more in HBP than NBP; P<0.05). CONCLUSIONS: Weight stigma increases cardiovascular reactivity among women with obesity and HBP in the laboratory and under ambulatory conditions. CLINICAL TRIAL REGISTRATION: Registered at ClinicalTrials.gov (Identifier: NCT04161638).

The Effects of Alpha-Glycerylphosphorylcholine on Heart Rate Variability and Hemodynamic Variables Following Sprint Interval Exercise in Overweight and Obese Women.

The current study examined the effects of Alpha-Glycerylphosphorylcholine (A-GPC) on heart rate variability (HRV) and hemodynamic responses following a sprint interval exercise (SIE) in women who were overweight or obese. Participants (n = 12, 31.0 ± 4.6 years; 29.4 ± 2.1 kg/m2) consumed 1000 mg of A-GPC or a placebo after eating breakfast in a randomized, double-blind cross-over design. After 60 min, participants performed two bouts of the SIE (30 s Wingate) interspersed with 4 min of active recovery (40 rpm). Hemodynamic variables and HRV domains were measured before and 60 min after the A-GPC consumption, immediately after SIE, and every 15 min up to 120 min during recovery. A-GPC consumption increased resting levels of both the time domain (Standard Deviation of RR wave intervals [SDNN] and percentage of interval differences of adjacent RR intervals greater than 50 ms [pNN50%]) and frequency domain (high frequency [HF] and low frequency [LF]) variables of HRV (p < 0.05). Moreover, HRV variables (except for LF/HF) decreased (p < 0.05) immediately after SIE in the A-GPC and placebo sessions. Systolic and diastolic blood pressure increased (p < 0.05) immediately after SIE in both trials. Both HRV and hemodynamic variables recovered (p < 0.05) faster in the A-GPC compared to the placebo session. We concluded that A-GPC consumption recovers HRV and blood pressure faster following strenuous exercise in overweight and obese women, and that it might favorably modify cardiac autonomic function.

Cardiometabolic Biomarkers and Habitual Caffeine Consumption Associate with the Adverse Ambulatory Blood Pressure Response to Strenuous Physical Exertion among Firefighters.

Caffeine has beneficial effects on firefighter job performance reducing fatigue and improving psychomotor vigilance. However, excessive caffeine intake may raise blood pressure (BP) following a bout of acute exercise among adults with elevated BP. The influence of caffeine intake on the ambulatory BP (ABP) response to vigorous physical exertion among firefighters has not been studied. In this sub-study we conducted secondary statistical analyses from a larger clinical trial (NCT04514354) that included examining the influence of habitual caffeine intake, and cardiometabolic biomarkers shown to influence BP, on the ABP response following a bout of sudden vigorous exertion over 19 h among firefighters. Previously, we found high amounts of calcium and sodium intake raised BP following a bout of acute exercise among adults with elevated BP. Thus, other secondary aims were to examine the influence of habitual calcium and sodium intake, and cardiometabolic biomarkers have shown to influence BP, on the ABP response following sudden vigorous exertion over 19 h among firefighters. Firefighters (n = 15) completed a Food-Frequency Questionnaire assessing habitual dietary intake over the past year. They randomly completed a maximal graded exercise stress test (GEST) and non-exercise CONTROL on separate non-workdays leaving the laboratory wearing an ABP monitor for 19 h. Prior to and immediately after the GEST, fasting venous blood was collected to measure lipid-lipoproteins, c-reactive protein, and blood glucose. Height and weight were taken to calculate body mass index. Repeated measures ANCOVA tested if the ABP response differed after GEST vs. CONTROL. Linear mixed models examined the relationships among caffeine, calcium, sodium, cardiometabolic biomarkers, and the ABP response following GEST vs. CONTROL. Firefighters were middle-aged (40.2 ± 9.5 year), overweight (29.0 ± 3.9 kg/m2) men with elevated BP (124.1 ± 10.3/79.6 ± 11.5 mmHg) who consumed 542.0 ± 348.9 mg of caffeine/day, about ~50% more than the dietary reference intake. Unexpectedly, systolic ABP was higher by 18.0 ± 6.7 mmHg and diastolic ABP by 9.1 ± 5.4 mmHg (ps < 0.01) over 19 h following GEST vs. CONTROL. We found 24% of the variance in the adverse ABP response to maximal physical exertion was explained by caffeine intake, and when combined with c-reactive protein, non-high-density lipoprotein-cholesterol, body mass index, blood glucose, and resting heart rate, up to 74% of the variability in the ABP response was explained. Additionally, we found calcium (ps < 0.001) and sodium (p < 0.0001) intake each explained up to 24% of the ABP response. Further investigation is needed in a larger, more diverse sample of firefighters to better establish how caffeine contributes to the adverse BP response to strenuous physical exertion.

Effect of Lower- versus Higher-Intensity Isometric Handgrip Training in Adults with Hypertension: A Randomized Controlled Trial.

This study compared the effects of lower- versus higher-intensity isometric handgrip exercise on resting blood pressure (BP) and associated clinical markers in adults with hypertension. Thirty-nine males were randomly assigned to one of three groups, including isometric handgrip at 60% maximal voluntary contraction (IHG-60), isometric handgrip at 30% IHG-30, or a control group (CON) that had been instructed to continue with their current activities of daily living. The volume was equated between the exercise groups, with IHG-60 performing 8 × 30-s contractions and IHG-30 performing 4 × 2-min contractions. Training was performed three times per week for 8 weeks. Resting BP (median [IQR]), flow-mediated dilation, heart rate variability, and serum markers of inflammation and oxidative stress were measured pre- and post-intervention. Systolic BP was significantly reduced for IHG-60 (−15.5 mmHg [−18.75, −7.25]) and IHG-30 (−5.0 mmHg [−7.5, −3.5]) compared to CON (p < 0.01), but no differences were observed between both the exercise groups. A greater reduction in diastolic BP was observed for IHG-60 (−5.0 mmHg [−6.0, −4.25] compared to IHG-30 (−2.0 mmHg [−2.5, −2.0], p = 0.042), and for both exercise groups compared to CON (p < 0.05). Flow-mediated dilation increased for both exercise groups versus CON (p < 0.001). IHG-30 had greater reductions in interleukin-6 and tumor necrosis factor-α compared to the other groups (p < 0.05) and CON (p = 0.018), respectively. There was a reduction in Endothelin-1 for IHG-60 compared to CON (p = 0.018). Both the lower- and higher-intensity IHG training appear to be associated with reductions in resting BP and improvements in clinical markers of inflammation and oxidative stress.

PTSD symptom clusters and cardiovascular responses to stress: Reactivity and recovery.

OBJECTIVE: Posttraumatic stress disorder (PTSD) symptoms are associated with high blood pressure (BP) and decreased heart rate variability (HRV) at rest and in response to acute stress. Unique contributions of PTSD symptom clusters to cardiovascular responses to stress are rarely investigated. This study tested whether PTSD-related arousal/reactivity drives relationships of higher PTSD symptoms with higher BP and lower HRV during rest, reactivity (stressor-induced change from baseline), and recovery. METHODS: Using a cross-sectional observational design, we enrolled 84 trauma-exposed community adults (83% female; 68% White; Mage = 35) who endorsed at least one core PTSD symptom. Participants completed a physical exam, self-reports of trauma history and PTSD symptoms, and BP and HRV frequency domain measurements during rest, stressor (mental arithmetic task), and recovery. RESULTS: Arousal/reactivity was not associated with BP or HRV reactivity but associated with a higher low (LF) to high (HF) frequency (HF) ratio (LF/HF) during recovery reflecting sympathetic predominance. During the stressor, more avoidance and intrusion were associated with increased diastolic blood pressure (DBP) from baseline; more avoidance was associated with parasympathetic predominance (lower LF/HF); and more negative cognitions/mood was associated with decreased systolic blood pressure (SBP), DBP, and LF from baseline. During recovery, more intrusion and negative cognitions/mood were associated with increased SBP from baseline; less negative cognitions/mood was associated with sympathetic predominance (higher LF/HF). CONCLUSIONS: PTSD symptom clusters demonstrated differential relationships with SBP, DBP, and HRV during reactivity and recovery. Findings may inform targeted PTSD symptom reduction interventions for disrupting links between PTSD and CVD risk.

Exercise to Treat Hypertension: Late Breaking News on Exercise Prescriptions That FITT.

ABSTRACT: Hypertension is the leading risk factor for cardiovascular disease and an independent predictor of mortality. The prevalence of hypertension has doubled in the last two decades and evidence suggests that almost half the individuals are unaware of their condition. The antihypertensive effects of exercise are now undisputable, and exercise training is recommended by the major professional and scientific societies, including the American College of Sports Medicine (ACSM), as first-line treatment to prevent, treat, and control hypertension. This review aims to overview the evidence supporting the current ACSM Frequency, Intensity, Time, and Type exercise recommendations for hypertension, discuss new and emerging evidence on exercise in the treatment of hypertension from our laboratories; and propose future directions of research integrating this new and emerging evidence.

The blood pressure response to acute exercise predicts the ambulatory blood pressure response to exercise training in patients with resistant hypertension: results from the EnRicH trial.

Reports suggest that the blood pressure (BP) response to an acute bout of exercise is associated with the BP response to aerobic training in participants with elevated BP. These associations have not been tested among patients with resistant hypertension. This study aimed to determine whether the BP response to acute exercise predicts the 24-h ambulatory BP response to a 12-week exercise training program in patients with resistant hypertension (n = 26, aged 59.3 ± 8.2 years, 24-h ambulatory BP 127.4 ± 12.2/75.6 ± 7.8 mm Hg) who completed the exercise arm of the EnRicH trial. Ambulatory BP measurements were obtained before and after the exercise program to assess the chronic BP response. To assess acute BP changes, resting BP was measured before and 10 min after three exercise sessions in the third week of training and averaged. The resting systolic (9.4 ± 6.7, p < 0.001) and diastolic BP (1.9 ± 3.2, p = 0.005) were reduced after acute exercise. The 24-h systolic (6.2 ± 12.2, p = 0.015) and diastolic BP (4.4 ± 6.1, p = 0.001) were decreased after exercise training. The reductions in systolic BP after acute exercise were associated with the reductions in 24-h systolic BP after exercise training (ß = 0.538, adjusted r2 = 0.260, P = 0.005). The reductions in diastolic BP after acute exercise (ß = 0.453, adjusted r2 = 0.187) and baseline 24-h diastolic BP (ß = -0.459, adjusted r2 = 0. 199) accounted for 38.6% (p = 0.008) of the 24-h diastolic BP response to exercise training. In conclusion, the magnitude of the BP response to acute exercise appears to predict the ambulatory BP response to exercise training among patients with resistant hypertension.